1. Field of the Invention
The present invention relates to a security system for protecting information stored in portable storage media, and more specifically, to a security system for protecting information stored in portable storage media by validating identifiers written in the storage media. The present invention also relates to a security system for protecting data stored in portable storage media by using cryptography.
2. Description of the Related Art
Today's mass storage device technologies allow a large amount of information to be stored into a handy storage medium, and new high-capacity media, such as magneto-optical (MO) disks, are used for delivering data and programs on an off-line basis. In business computer systems in which a plurality of terminals are connected to a host computer via communications networks, executive programs for the terminals, as well as data processed in daily jobs, are stored in those portable storage media and transported from headquarters to terminals or vice versa. Besides being capable of storing large-volume files, they are easy to carry, store, and use.
In business activities, however, data security will be a serious concern because of a confidential nature of the contents of data files. Since there is always a risk that such important storage media might be lost or stolen in transit, password protection techniques are commonly used to protect information in the media from unauthorized access and to ensure reliable delivery. A password, or a uniquely defined identifier, is previously written into the storage media, and a user attempting access to the contents will be required to enter the correct password.
This conventional password protection is simple and easy to implement, but it should be noted that such a password is also a potential subject of theft and illegal use. Particularly in the case that data and a program for its retrieval are packaged in the same medium, the data will be exposed to more serious risk and threats, since any terminal equipment can be used for retrieving the data. Therefore, there has long been a demand for more reliable security systems to protect information in storage media from unauthorized access and to ensure safe delivery.